Replacing a TreeNode by index in a TreeView adds a blank space below node

.NET version

7.0.100-preview.5.22307.18

Did it work in .NET Framework?

No

Did it work in any of the earlier releases of .NET Core or .NET 5+?

No

Issue description

When setting a new TreeNode by index in TreeNodeCollection, the old node seems to be not completely removed, leaving a blank space. It also creates an issue from accessibility side, because focusing on this blank space with Narrator throws an unhandled exception.

Actual behavior: Button click executes following code:

treeView1.Nodes[0] = new TreeNode(new Random().Next().ToString());

• New blank space is added every time node is replaced
• App throws an exception when blank space is focused with Narrator
• There is a memory leak because old node’s accessible object is not disconnected

Expected behavior: Button click executes following code to show expected behavior:

treeView1.Nodes.RemoveAt(0);
treeView1.Nodes.Insert(0, new TreeNode(new Random().Next().ToString()));

• No blank space
• No exceptions with Narrator
• Old node’s accessible object is disconnected preventing from memory leak

Also, replacing an item by index in other collection-based controls like ListView or ListBox works without issues.

Steps to reproduce

Run attached project, click on the Replace button.

TreeViewReplaceBug.zip

[Nora-Zhou01]

Verified on .NET 8.0 latest build from main branch: NET 8.0.100-alpha.1.22451.15, issue was expected, test result is same as above screenshot.

[Tanya-Solyanik]

@MelonWang1 - thank you for the additional investigation!